


A Bath

by choklitcake



Category: Sherlock (TV)
Genre: Bathing/Washing, Emotional Hurt/Comfort, Hurt/Comfort, M/M
Language: English
Status: Completed
Published: 2012-10-22
Updated: 2012-10-22
Packaged: 2017-11-16 19:42:20
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,156
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/543140
Author URL: https://archiveofourown.org/users/choklitcake/pseuds/choklitcake
Summary: <blockquote class="userstuff">
              <p>John is roughed up and Sherlock bathes him, if only to reassure himself that there's something real left for him not to hate.</p>
            </blockquote>





	A Bath

**Author's Note:**

> This is my first post to AO3. Hopefully you enjoy. John is a patient soul.

_Tick._

_Tick._

_Tick._

The clock on the mantle makes itself known, a soothing presence of ambient noise.  Calm, reliable, steady.  After pulling his chair to face the sofa, Sherlock sits down, his face whitewashed with agitation.  His mercurial eyes pierce John from five feet away, his expression is still stricken.

John feels like he should say something to break the dour mood, but he doesn't really know what, other than _It's going to be fine now_ , which would be an overtly obvious statement that Sherlock would not appreciate, he figures.

Sherlock has propped his partner up on the sofa with great care, pulling the coffee table closer so John has somewhere to rest his swollen ankle.  John had caught a glimpse of himself in the mirror as he shuffled into the flat, Sherlock helping him up the stairs, stooped to accommodate his arm around his long neck.  Even from across the room, John could see the ligature marks around his own neck.  He doesn't relish the thought of seeing them up close.  The sensitive area of his neck, right under his jaw, is still throbbing pretty badly.  His voice is hoarse and strained, although breathing is much easier than it had been even an hour ago.  He is sore, and exhausted, but he is home with Sherlock now.

Sherlock, whose watery expression is currently reminding John of a large fish tank he had as a child; Harry used to peer at him from behind it, the lines of her face cloudy and undulating, much like Sherlock’s are now.

John did get bruised up a bit; he knows it will take him a few days to recuperate.  He was tripped and taken out from behind while running down a dark alley (really, where else?), punched when he wasn't looking.  John's fairly good with self-defence, but he is a bit out-of-practise these days, admittedly.  Before he even had a chance to react, another attacker appeared and it was two against one, and then a rope or something was wrapped around his neck.  He was nearly strangled.  His memory from there on is a bit of a blur, but he remembers Sherlock yelling a lot, his eyes glowing yellow.  To or at whom he was yelling, John isn't certain.  To his attacker, or into his mobile, or perhaps to John himself?  It wasn't important anyhow, John supposes.  The disturbing image of Sherlock's normally cool, collected visage screwed up and blown out with rage and horror will stick in his mind for a while though, that much was certain.

John remembers being transported to the hospital, though.  Just those few minutes after waking up are missing.  That means he only could've been out for a few moments, thirty seconds tops.  Not enough for permanent damage, just enough to keep his brain from recalling immediately afterwards.  He visited the hospital, they sent him home after a few hours.  No lasting damage, just discomfort and a good scare.  And a few bumps and bruises, and a small superficial gash on the front of his throat where Sherlock had gotten a little overzealous in cutting the ligature away.  John can't really fault him for that, though.  If the roles had been reversed, John might've accidentally cut through Sherlock's spinal cord trying frantically to get air back into his lungs and blood back to his brain.

Now all that is left is a twisted ankle and some nasty-looking marks, and the burning around his neck.  John has some pain meds and should probably get to them, but right now he doesn't have the energy to do anything other than lay there.  He wouldn't mind sleeping out here on the sofa, right where he is, but that probably wasn't going to happen.  Sherlock would insist upon sleeping out there to keep an eye on him, and then of course he wouldn’t really sleep at all.  No, Sherlock will need to help John get to bed at some point.

Sherlock, who has been staring at John in silence since he deposited him on his spot on the sofa.  John has been watching him in his peripheral vision.  He's just staring.  Who knew what kind of rockets were firing off behind those eyes.  Finally John turns his head and looks at him squarely.

Sherlock is examining him so intensely that John isn't sure he'd actually registered John's head turning to look back at him.  His expression is raw, severe.  His brows are knit with concern.  There aren’t tears or any traces of sentiment like that, but the rims of his eyes are quite red and his nostrils are flared.  He works his jaw a bit.

John had nearly died in his arms today.  Amazing, John thinks, how something so harrowingly romantic almost happened to someone as ordinary as he.  It was painful, and frightening, but he really is going to be fine now.  Surely Sherlock ought to know that.  Right?

"Sherlock," he gathers up the energy to croak out.  He doesn't get a response.  "Sherlock," he tries again, a bit louder.  Sherlock finally seems to snap out of it.  His eyes meet John's before quickly darting away again, but he doesn't speak.

"It's Sherlock," Mrs Hudson had said to John once.  "Who knows what goes on in that funny old head of his."

The minutes go by, punctuated by the comforting familiar tick of the clock, and John begins to slump and doze off in spite of himself.  He is still in his outerwear and not very comfortable, but the retreating adrenaline is leaving a void in him that can only be slept away.  Presently the soft rumbling of Sherlock's voice throws a line out to him and he's pulled away from the brink of unconsciousness.

"John."

"Hmm?" John forces out, dragging his eyelids open.

"John," Sherlock's voice is gravelly, but tender.  He sucks in a breath.  "John, I'd... I'd like to bathe you."

John is completely awake now.  He straightens up just a bit.  _Bathe me?_ he thinks.  In the time that they'd been romantically linked, John has learned a few things, and one of them is that any threat to John pushes Sherlock from everyday insecurity over the threshold into a bit jealous and sometimes possessive behaviour.  One time several months ago John was kidnapped for a few hours, emerging a bit shaken up but otherwise no worse for the wear, and he couldn't get Sherlock off of him for days.  He didn't sleep the entire night afterward because Sherlock wouldn't let him.  _You are mine_ , Sherlock had murmured over and over, pinning him down and marking him humanely but firmly with nails, teeth, slaps to his rear.  John hadn't quite known what to think of it, especially given how shy and green and downright _delicate_ his flatmate had been when they first began a romantic sexual relationship.  True, the experience had been disturbingly pleasant on some levels, but the bite marks had lasted for days, and it had been an argument just to get Sherlock to let him out of the flat to do the shopping.  And that was just because of a mild uneventful kidnapping.  John isn't sure he wants to find out what this case of actual potentially serious bodily harm would cause Sherlock to do in retaliation, especially when John needs rest so badly.

So, "That's very sweet of you, Sherlock, but I think it can wait for tonight," John says.  Of course he needs to be cleaned up a bit but he can barely find the strength to speak to his companion, let alone stand in a hot shower.  And that isn't even taking into consideration the twisted ankle.

"John," Sherlock says again, closing his eyes and furrowing his brows deeply, as if he is saying something painful.  "I wish to bathe you this evening."

John watches with mild alarm as Sherlock becomes more and more agitated.  He has to quell him somehow.  He's in no condition to deal with the situation if Sherlock goes out and does something stupid.  And in any event, if he is going to shower, it probably would be helpful to have a second person in to help him with his ankle, he supposes.

"Well, let's go hop in the shower then, before I nod off--"

"No," comes Sherlock's clipped reply.  "In the tub."

“There isn't enough room for both of us in the tub.  We tried it once, remember?"  That had been a disaster.  Sherlock had cooked up some elaborate story in order to explain to Mrs Hudson why there was water damage to her ceiling.  She had threatened to raise the rent, and John was quite surprised she hadn't.  There was just too much man for one old tub to hold without sloshing water everywhere.

"I'm not going to be bathed."

John blinks.  "What?  You want to bathe me in the tub, like a child?"  John says it softly with a smile on his face, but Sherlock apparently thinks he's ridiculing him.

" _Please_ , John."  He says it very lowly, looking very grimly serious.  John hesitates for a moment.  What is he after, he wonders.  Not sex, if Sherlock wouldn't be getting into the tub.  That at least is good.  John couldn't handle sex right now.  But why did Sherlock want to bathe John?  Perhaps to see for himself that he was okay?

_I'm fine, Sherlock.  I'm alive.  Please don't look so devastated._

"Well," John says, after a bit of a pause.  "Go draw the bath, then."

Sherlock peers at him for another moment and then gets up to draw the bath.  His footsteps are weighty, ominous, full of purpose.  John smiles fondly at how melodramatic the git can be.  He hears muffled noises of a bath being drawn coming through the walls, the pull on the shower curtain, the squeak of the faucets, the rush of water as it fills the ancient bathtub.  He leans back into the sofa, relaxing a bit.  A hot bath did sound lovely.

Sherlock comes back in and helps John up.  It will take a bit of maneouvering to get him into the bathroom, let alone the tub.  John knows his foot will need a brace, but right now it's too swollen, so he has to be very careful not to bend it or put any weight on it.  Initially, he's nervous about Sherlock handling him in that state; his taller companion's movements are typically dexterous and fleet, but when he becomes agitated and his control slips he can be a bit rough without meaning to be.  To John's relief he helps him to the bathroom gently, gingerly, his touch soft but strong and firm, handling John as though he were a precious trinket that could break at any slight mishandling.  John's a bit moved; he hadn't realized that Sherlock, for all his fire and brimstone, could be so tender.

Sherlock sits John down on the toilet lid and helps him remove his clothing.  John got a better look at himself in the bathroom mirror and it isn't a pretty sight: the ligature marks, the gash, the bruising, a few small cuts on his cheek that he didn't know were there.  His eyes are bloodshot from the pressure of attempted strangulation.  His hair is an absolute mess, although that's the least of his concerns.  His head feels so heavy and it keeps rolling around on top of his shoulders until Sherlock leans forward, offering his shoulder for support.  John gratefully lays his head upon it, trying to calm the vertigo that's setting in from sitting upright.

After Sherlock removes John's jumper and shirts, he puts a hand on the back of John's neck, cradling his head, and kisses him rather chastely on the mouth.  He remains silent whilst doing this, his eyes still rimmed with red and appearing glassy, but not leaking.  He seems quite intently focused on his task, John observes.

Sherlock unzips John's flies and moves his partner's hands to wrap around his neck for support, pulling John up so he can pull his trousers and pants down past his knees before setting him back on the toilet lid again.  He then pulls the fabric off the rest of the way, taking care not to disturb John's ankle.

The tub is filled now, so he shuts off the faucet.  John is surprised to note that Sherlock has added bubble bath to the water.  A small mountain of foamy bubbles floats serenely on top of the water, crackling softly in the hazy heat of the bathroom.  How silly and frivolous it seems, given the day they'd had.  Come to think of it, John hadn't even known they had bubble bath in the flat.  It's a bit endearing and unexpected.

Pulling John's arm around his shoulder for the fourth or fifth time that day, Sherlock helps his companion up to perch on the curved edge of the tub; John steadies himself with his free hand and unaffected foot.  Slowly, carefully, they lower him in bum first.  The water is quite hot and John hisses a little, his skin prickling with the sensation, but he slowly eases into it with a soft exhale as the water moves to cover his skin, rushing up to fill every nook and cranny on his battered body.  John feels a little sheepish at his own breaths and small vocalizations, which in another context could be considered quite erotic in nature, but Sherlock doesn't comment.  John's swollen ankle stays out of the tub, but his other appendages find their way in, and he sighs and leans back into the speckled porcelain.  He's relaxing, finally, really relaxing for the first time since the ordeal ended.  They had cleaned him up a bit at the hospital but he hadn't had a bath, and of course no one ever really relaxes at a hospital anyway, especially not doctors.

His eyes roll lazily in their sockets to look up at Sherlock, who is leaning on his bare forearms over the edge of the tub.  He's rolled his expensive shirtsleeves up so they don't get wet, but a few splashes from the bath have found their way to him anyway, marking his shirt a dark purple in spots.  He's peering down at John, his dark curls going a bit frizzy in the humidity of the bath, the corners of his mouth turned upwards a bit.  He's pleased that John is comfortable, but his expression is still severe and his nostrils are still flared.

John's heart aches at the sight.  Instinctively, he reaches up and brushes his thumb across Sherlock's cheek.  It suddenly occurs to him that, no matter how vulnerable and helpless John might be at the moment, naked and injured and splayed out in a steamy bath, Sherlock is feeling just as vulnerable, if not more; his usually vice-like grip on himself is weakened, his emotions smeared all over his face like garish make-up.

"Sherlock," John reminds him gently, "I'm okay."

His voice snaps Sherlock out of it, seemingly, as he sets to lathering a sponge, keeping busy as if to push away unpleasant memories.  John knew he wouldn't want to talk about it, but they’re going to have to, eventually.  Sherlock fancied himself above emotions, but it simply wasn't true, and he couldn't keep suppressing them like this.  He _had_ to learn productive ways to deal with it.  John put up with Sherlock's lack of emotional finesse, but that didn't mean it was healthy.

But as John begins to speak, Sherlock interrupts him.

"Is the temperature alright?"  It's an unnecessary question.  Anyone watching would be able to deduce the temperature was perfect, based on John's reactions-- let alone the great Sherlock Holmes.

"It's fantastic Sherlock, thank you."

He starts with the fingers, of all things, pulling each of John's weathered hands into his pale ones, running the sponge softly up and down his arms, leaving cushy lather in its wake.  From there he works on John's chest and neck, taking painstaking care to touch very gingerly around the ligature marks.  John remains silent, just watching him, his eyelids growing heavy once more.  Thoughts slosh around in his brain.  It's quite an intimate act, the realization comes, letting someone else wash you.  Perhaps, in some ways, more intimate than sex.  It involved giving up a bit of control and a tremendous amount of trust.  John feels fairly defenseless at the moment.  Perhaps Sherlock was sensing the same thing, because his cheeks were tinged a light pink.  Could be that or simply just the heat, John supposes.

Sherlock moves on to John's feet, barely disturbing the injured one but scrubbing the other quite clean.  Rolling his shirtsleeves up further, he lathers John's legs before delving down to where they meet John's body.  He doesn't linger there long; his intent isn't to titillate, not with John in the current condition.  John tenses to move himself a bit to give his partner better access, but Sherlock holds him down with a strong but gentle hand.

"It's fine," he says simply, and John relaxes once more.

Once Sherlock has cleaned John's body to his liking, John figures they're through.  He steels himself to get out of the warmth of the bath, ready to endure the chill until he gets ahold of his dressing gown.  But to his surprise, Sherlock reaches for a cloth on the rack above the tub and wets it with a little soap, wringing out the excess moisture before coming for John's face.  Of course a man with an eye for extreme detail like Sherlock wouldn't let John's face go untouched.

Steadying the sandy-haired head in front of him, Sherlock very seriously sets to work with the cloth, wiping the dirt and pain of the day from the face of the man who means more to him than anyone else ever would, or ever possibly could.  John knows that Sherlock is quite out of sorts, that much is obvious, but what he doesn't know, what he could never know,  is the depth of the _hate_ Sherlock has bubbling away inside of the cauldron of his mind right now.  The hate, and the fear (although Sherlock didn't often openly admit to fear, not usually), the sense of possessive anger, and the chilling, mind-bending _horror_ of what had transpired that day.  And not only of that, but of the fact that Sherlock hadn't even stopped to consider before that John might someday not be there.  How could he have never thought of that before?  How in God's name had that thought never crossed his mind?  John was always with him, and that meant things were always as they should be, as far as Sherlock was concerned.  That things might not always be aligned in that state of rightness... how did Sherlock Holmes manage to miss a possible outcome as obvious as that?

Sherlock is a damned fool.  He hates everything.  He hates the _vermin_ who dared lay their grimy fingers on John, he hates the darkness for setting up the alleyway for the crime, and Christ he even hates the ligature (plaited rope, nylon, the attacker stole it from his brother, who was an arborist) for daring to exist in this miserable world, hates the machine that wove the fibres of the rope together, hates the man who invented the machine.  But most of all, he hates himself.  He hates himself because, although he's doing a good job of making it appear he's bathing John for his benefit, doing something nice for him, he's actually doing it to reassure himself.  Sherlock is so predictably, dully, _hatefully_ weak.  In his failure to calculate all possible outcomes he failed protect John, and no matter how hard he tries, it will probably happen again.  And the next time, there may not be a body for him to bathe afterwards.  Sherlock is cowardly.  This is why he can barely speak: he's too busy _hating_ , and nothing breaks through Sherlock's inward focus.  The fact that he wouldn't even know how to begin articulating his abstract fears and frustrations into words crosses his mind, and he hates everything more.

And he's afraid that if he opens his mouth, he'll either wail out in despair or do the one thing a man such as himself doesn't do, and weep.  So he keeps his jaw set, his lips pushed tightly together in a fine line, and tries with all of his might to oscillate focus outward, on the task at hand, while actively avoiding meeting John's gaze.

Of course, washing his lover's face, it's impossible to avoid eye contact.  Sherlock's eyes roll up from John's lips, over the premature lines on the handsome face that he's taken great care to memorize, to smart, grey-blue eyes where his gaze is immediately sucked in, like a sinkhole opening up and pulling his soul from his body; the force of it takes his breath away.  They stare at each other for a long moment, Sherlock's expression frightfully unguarded. 

Sherlock is proficient at hiding his emotions; he wasn't born that way, he's learned it over countless years of emotional distancing and alienation.  Control over himself is something he prizes perhaps above anything, and it actually caused some friction early on in their relationship.  His inability to open up triggered some insecurity in John until Sherlock learned (very slowly) that he could trust John with his stickier, hatefully human side, and slowly let his guard down.  But he never let it down all the way, not really; there was always a thin wall left standing between the two of them to the point that John never knew precisely what Sherlock was feeling at any given moment unless Sherlock made the decision to expressly tell him.  Until now.  Sherlock knows he is being read like an open book, and it's terrifyingly new, being on the other side.  He feels peeled open, metaphorically bent prostrate before John, and he can't tell if he feels more mortified or freed. 

John just smiles, as he is wont to do, and leans his head into Sherlock's hand, reaching up to brush some frizzy curls out of his lover's eyes, not caring that his hand is wet.

"Don't be frightened."

"I'm not _frightened_ ," Sherlock snarls, spitting the word hatefully.  John knows he's hit the nail on the head.

"It's okay to be."

"I'm _not_."  The insistence upon the lie sounds absurd even to his own ears, but Sherlock would never admit it.  John knows; Sherlock doesn't have to voice it.

"I love you."  It's a soft whisper, the words warm and wet in his mind like John's hand on his face.  Sherlock absolutely cannot respond.  Even helpless in a bath (Sherlock was deathly jealous of that bathwater, the way he was jealous of John's clothes and John's food), _John_ is reassuring _him_.  Oh, the _hate_.

He wipes down the rest of John's face, even scrubbing in John's ears like a mother might do to her toddler.  John scrunches one eye shut as the cloth-covered fingers sweep inside of his ears, tickling a bit.  Then Sherlock abandons the cloth and reaches for a cup they keep near the sink, filling it with bathwater and pouring it over John's head.  John looks a bit like a shaggy dog as his fringe sticks to his forehead (his hair's a bit on the long side these days, for him anyway) and he feels a little sheepish but pleasantly surprised as Sherlock's long, shampooed fingers rub at his scalp, working up a lather.  John leans into the touch and feels his neck muscles unwind a bit.  The ten small points of pressure wind and bob around his head, rubbing, feeling, cleaning, making him shiver.  Sherlock doesn't miss a single spot on his scalp, rubbing behind his ears, his temples, even back on the occipital ridge, giving John gooseflesh.  Some more dunks of the cup and John's hair is clean and rinsed.  He smiles gratefully up at Sherlock, quite surprised but touched at his caring behaviour.

In spite of his loving ministrations, Sherlock still looks deathly grim, and a heavy silence still permeates the air.

"The bubbles were a nice touch," John says.  His voice is still quite rough-sounding so he's not sure if it's doing much to lift the mood, but he has to try.  "If not a bit homey.  I was wondering if you were going to put a shower cap on me."

It's not that funny, but Sherlock titters like a schoolgirl, high-pitched and manic.  It's disturbing.  John watches with growing alarm as he keeps _giggling_ , putting the cup down and running shaking hands through unruly raven hair before scrubbing them across his own face.  His dark laughter breaks up into chunks until it sounds more like sobbing.

John numbly wonders if this is the event that will sever Sherlock Holmes' last fragile strand of sanity, although on some level he's relieved to see Sherlock snap, cutting the tension that's been building over the past few hours.

"Bloody hell, Sherlock, calm dow-"

"'Calm down'?  'Calm down'?!" Sherlock repeats, his voice growing louder and more frenzied.  "I just watched someone nearly wrench you away from me and I'm supposed to laugh and pretend that it's to be expected?  You are _mine_ and-" he grits his teeth and begins to shout, slamming his fist on the side of the tub, making John jump a little- " _they tried to sever you from me._   The _gall_.  The _sheer audacity_..."  He bites off his sentence, already feeling exposed enough.  He's breathing rapidly through his nose, his lips ground together in a tight line.  "This wasn't supposed to happen.  Never.  Not to you."

Sometimes John can't believe that Sherlock claims to be unsullied by human emotion.

"Take it easy," he scolds gently.  "If you hurt yourself I'm in no shape to patch you up."

Sherlock interrupts him.  "Not only the fact that they tried to take you, they _thought_ they could and they almost did.  John," he says, voice fraying.  "John... I thought..." 

John waits for the complete thought, but Sherlock refuses to continue.  He seems to have run out of steam.  He leans against the side of the tub, resting his head in his hands, running pale fingers through unruly dark hair.  John wants to wrap him up tight in his arms; Sherlock is nothing if not an intense person, and seeing him in a mood can be truly disturbing.

"Sherlock," he starts, reaching out to grab at his hands.  "It's alright, I'm fine.  I am going to be just fine, and everything will be okay."  It sounds trite, even to John's ears, but it's the simple truth.

Sherlock explodes again, frothing.  " _They almost took you_ \--"

"But they didnt!" John yelps back.  That hurt his throat a bit.  Sherlock is silent as John coughs reflexively, trying to get his throat to feel right again.  Sherlock puts a hand to his back and John continues where he left off.  "They didn't get me, Sherlock.  I'm here, and I'm fine."  Sherlock looks away, the muscles in his face trembling.  "It's okay to be scared, or angry, or anything else, even if you don't care to admit you are.  I am too.  But there's nothing more to be done now.  I'm back, and I'm yours... and no one can take that away from you, even if they kill me."

Sherlock's mouth opens a little and his breathing calms as he considers this.  "You're right," he breathes, eyes twitching.  "They can't take that away from me."

John smiles softly, laying his head back on the tub again.  "No, they cant."

"Even if they kill you," Sherlock echoes, a bit disturbingly, John must admit.  Bit not good.

They sit there in silence, gazing at each other as the last of the bubbles in the bath crackle and disappear.  This man, John thinks.  This man before him is something else.  Scoffing at emotion and sentiment when he builds such frightening emotional sandcastles around himself.  Only John could watch them fall and not be spooked.  Only John could reassure him and quiet his unspoken fears.

Suddenly, Sherlock leans forward and puts his hands on the sides of John's face.  He leans in to take John's bottom lip between his, and then states plainly, "I wish to mark you."

John smiles patiently.  "Another time.  I've had enough marking for one day, I think."

Sherlock doesn't argue with that, but looks at him for a long minute.  It's not enough, this bathing thing.  He has to show John what he means to him.  Has to show himself.

John waits for him to speak.  "John, you must..." he starts, his tone charmingly needy.  "When you are fit again, you must let me have... an evening with you."  That sounds ridiculous, Sherlock thinks darkly.  John couldn't possibly know how badly he needs this-- to mark John, to slowly strip him and push him down and climb on him and _feel_ him, _smell_ him, to examine him closely as though he were smeared across a glass slide, to lay on top of him and fuse to him the way a skin graft fuses on an injured limb, to slide in and around him the way the elemental bathwater had filled in and around his body.   To have John...

"To myself," he explains. 

Sherlock is a lucky man.  "Sherlock, I promise that when I'm back to my full strength, we'll have an evening entirely to ourselves, and you can wrestle with me or mark me or do anything--" He catches Sherlock's expression perking up and corrects himself quickly.  "Well, almost anything, you please."

"Thank you," Sherlock rumbles, his voice catching in John's chest as he leans in to smell John's neck.

"Easy," John winces, and Sherlock eases up but doesn't pull his head entirely away.  They sit there that way for a minute or two, John ruffling Sherlock's ridiculous hair and Sherlock drawing comfort from being close to John's body.

The water starts to cool so Sherlock pulls the plug out of the drain and helps his companion change into his pyjamas and get into bed.  Sherlock showers, frantically trying to scrub the day off of himself, until he's a bright pink.  Then he climbs into bed with John, who has already fallen off the cliff of consciousness.  Sherlock siddles in right next to him, keeping his face close to John's damp head.

Sherlock is a scientist, and so he knows all about the mechanisms of olfaction.  The fact that he can smell John in this moment means that odourous molecules have transported into his nasal cavity to the olfactory epithelium, where they binded to receptor proteins in the cilia, initiating an electric signal that travels to the brain and is interpreted as a scent.

In short, he can smell John, his clean skin, his shampoo, simply because there are literally pieces of him in his nose.

He keeps this thought to himself but it's ultimately what allows him to sleep.


End file.
